1. general organisation of H&N - major muscle groups Flashcards
what do the main muscles in the head comprise of?
muscles of facial expression
muscle of the cheek (buccinators)
occipitofrontalis muscle
muscles of mastication
where do muscles of the face lie?
in subcutaneous tissue
where do most muscles of face attach to?
bone or fascia
how do main muscles of the head produce their effects?
by pulling the skin
what do main muscles of the face surround? act?
surround the orifices of the mouth, eyes, nose
act as sphincters and dilators that close and open the orifices
what is the function of the buccinators?
keep the cheek taut and aid in chewing
what are the muscles of mastication supplied by?
mandibular division of the trigeminal nerve (branch of CN V)
what does the facial nerve (CN VII) supply?
superficial muscles of the neck + chin (platysma) muscles of facial expression buccinators muscles of the ear occipitofrontalis muscle
where does the facial nerve enter after it exits the cranium? what happens after?
enters the substance of the parotid gland
divides into its 5 extracranial branches
what happens when there is injury or pathology affecting the facial nerve?
cause weakness of the muscles of facial expression on the ipsilateral side
what is the most common non-traumatic cause of facial paralysis?
inflammation of the facial nerve near its exit from the cranium at the stylomastoid foramen (Bell’s palsy)
what does inflammation of the facial nerve near Bell’s palsy cause?
inflammation causes oedema and compression of the nerve in the intracranial facial canal
what happens as the facial nerve and its branches run through the parotid gland?
lie relatively superficial so vulnerable to damage in injuries to the face and in disease or surgery of the parotid gland